In an electrical utility grid, poor electrical conductivity may result from improper wire splicing, tapping, connections or cable aging. Such poor electrical conductivity results in high impedance. When current is drawn through a high impedance connection, there is a voltage drop across the connection and associated heating. Heat may further degrade the connection, causing the high impedance connection to become even more impeded. Deterioration of a high impedance connection can occur over a period of hours, days, weeks, months, or years, depending upon the nature and problems of the connection, and the magnitudes of the currents (loads). A high impedance connection can result in energy losses due to heating, and can result in voltage problems due to excess voltage drop across the connection. Both of these problems may worsen as the connection deteriorates.
Energy losses also result from theft. In one example, energy diversion results when an unmetered load is attached to the secondary of a transformer. Because the load is unmetered, normal billing procedures are not performed. In a second example, energy diversion results when a “rogue” or unauthorized transformer is attached to a primary power line, and unmetered loads are attached to that transformer's secondary.
Thus, energy losses may result from high impedance connections and from unmetered loads. Both result in financial losses to utility companies, and both may involve unsafe wiring conditions.